Propeller pitch reversing control switch



DeC- 18, 1951 L. J. BoRDELoN PROPELLER FITCH REVERSING CONTROL SWITCH 2SHEETS-SHEET l Filed March 3l 1949 INVENTOR. fans/rencel J. orde/o/l BYY v nmwzy I .JQ BORDELON 2,579,172 PROPELLER FITCH REVERSING CONTROLSWITCH Filed March 3l, l49

D ec. 18, 1951' 2 SHEETS- SHEET 2 GOV EEN OR /7/- l @lL/'37- T l /74 [53a I /aa- DI! 52 PROPELLER? f Y fw Powelz Sw: my Y f5; ifi g 44 Y 523164/2 ,06 H3 M0 JNVENTOR.

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Patented Dec. 18, 1951 PROPELLER PITCH REVERS-ING vCONTROL SWITCHLawrence J. Bordelon, San Diego, Calif., assignor to Consolidated VulteeAircraft Corporation, San Diego, alii., a corporation ofDelawareApplication March 31, 1949,'Serial No. 84,565

11 Claims. (Cl. 20d-153) This invention relates to hydraulicallyactuable controllable pitch propellers and more particularly to improvedcontrol means for eiecting the operation of a propeller of the characterndicated.

An object of the present invention resides in the provision of apropeller pitch controlsystem having control devices for attaining pitchreversal of the propeller blades.

Another object of this invention is to provide an electrical controlinstrumentality of improved construction operative to control themovements of the blades of a hydraulically actuated propeller into andout of reverse pitch positions.

Another object of the invention resides in providing a controlinstrumentality of the character indicated having the operation .thereofunder the control of the usual engine throttle lever.v

Another object of the invention lies in providing an electrical controlinstrumentality embodying a plurality of electric switch units andelectromagnetic switch means electrically associated and all beingoperative by a common actuating means.

A further object of the invention is the provision of an electricalcontrol instrumentality for controlling the operation of a reversingtype hydraulically actuable propellerwhich is of simple, compact andeiiicient construction.

Other objects and features of the present invention will be readilyapparent to those skilled in the art from the following specication andappended drawings wherein is illustrated a preferred form of theinvention, and in which:

Figure l is a perspective view of an electric control instrumentality inaccordance with the'invention.

Figure 2 is a vertical sectional view through the instrumentality.

Figure 3 is a detail view in perspective illustrating the actuatorarrangement for the electric switch units of the instrumentality.

Figure 4 is a detail view in perspective showing an armature andassociated movable contact assembly for use in the electric controlinstrumentality of Figure 1.

Figure 5 is a diagrammatic view showing a hydraulically actuatedcontrollable pitch "propeller and a pitch reversing control systemassociated therewith.

Figure 6 is a diagrammaticillustration of the electrical controlinstrumentality showing the relative positions of the Variousoperatingelements for moving the propeller into reverse pitch Figure 7is a View .sirnilf-Iv t0 iere. d but with the operating elementsillustrated inthe relative positions assumed when the propeller is beingmaintained in reverse pitch position.

Figure 8 is another diagrammatic View of the electrical controlinstrumentality showing the positions of the operating elements when thepropeller isbeing moved from reverse pitch to normal position.

Figure 9 is a diagrammatic View showing the static positions of theoperating elements of th electrical control instrumentality; vand Figure10 is a wiring diagram of the reverse pitch'control circuit .-shown inassociation with thefeathering control wiring circuit for the propeller.l A

Particular reference is now directed `first to Figure', wherein is shownan aircraft power plant comprising an internal combustion engine,generally indicated at II); which engine I0 is equipped with ahydraulically actuable controllable pitch propeller II. Propeller II hasa propeller hub I2 to which is movablysecured a plurality of propellerblades I3 adapted to rotate about their .longitudinal axes to changetheir pitch angle or angle of attack. Suitable hydraulic pitch chang.-ing mechanism, indicated generally at I4, is containedfwithin a dome YI5and includes a'piston I6 reciprocablein a cylinder I'I. Piston ISiSmadeto move within its containing cylinder Il by the force exerted byhydraulic iiuid supplied under pressure to the opposite ends of thecylinder I'l. Piston I6 is suitably operatively connected tothepropeller blades` I3 through a rotatable member I8 carrying gear meansI9 which are adapted to mesh with usual beveled gear means. (not shown)provided on the inner orvbase ends of the propeller blades I3." Thepiston I6 is joined'to the rotatable member I 8 through a camfollower-cam track arrangement 20 for effecting rotation of member I8upon reciprocating movement of the piston I6. .This organization ofelements acts to convert reciprocable` movement o'f piston I6 intorotative, pitch changing' movement ofv the propeller blades. I3. For amore detailed description of the arrangement of the propeller blades andthe .operative Vconnection thereto of the actuating vmechanism referencemaybe had to UnitedStates Patent No'. 2,'361,954,'issued November '7,1944 for Propeller Control Means.

A suitable governor 2| conveniently mounted on the engine I0 acts tosupply iiuid to pitch changing mechanism I4 to automatically'effectadjustments `in propeller blade pitch necessary to maintain .constantengine speed under varying Hightv .'conditionsThe' fluid provided by thethe governor 2| is adapted to operate to pass oil through conduit 22 tothe inboard side of piston I6 to provide pressure tooause` thepropellerv blades I3 to move to a lower pitch whereupon engine speedincreases.

With an 'overspeed con'- dition the governor 2| will respond todirectvoil through conduit 23 to the outboard side of piston I6 to causepropeller blades I3 to move to a higherv pitch, thereby decreasing theengine speed. The particular construction ofthe governor 2|, it isunderstood, forms no part of the present invention as it is contemplatedthat such usual governors may be employed as are adapted, in responsevto external conditionato cause fluid to be .passed to lone or the otherof the two conduits 22 and 23 connected to the pitch changing mechanism|4. The governor 2| may convenientlyassume the form and construction' asfully described in a manual entitled Propeller Hydromatic Governors No.123, published by .Hamilton Standard Propellers of East Hartford,Connecticut. Associated with governor 2| 'and vthe controllable pitchpropeller lI is a control system, indicated generally by the numeral 25,which is adapted to accomplish movement of thepiopeller-blades I3 Afromtheir .normal range 'to their reverse pitch positions. Positioning' ofthe propeller blades. I3 in reverse pitch serves a primary desirable.function in reducing airplane landing -speeds and runs. The attainmentof this condition must Vbe rapid, efficient and certain and the controlsystem 25 provided by this linventionis all this.

The control system `25, ras shown, includes ka suitable gear type pump26. drivenbyan electric motor 21. It is here noted tlriat: this pump 26used in 'the reversing operation is the same pump which is used for thefeathe'rmg operation, so the reversing operation does not require aseparate pump. A fluid line 28 connects the inlet of pump 26 with thesump of fthe oil tanky 3| which may be the source of supply for 'theengine lubrication system. The pumpl is connected through a conduit 32to the governor 2| wherebyauxiliary oil is supplied Vto the governorV2"I "to supplement the normal cil output of the governor, whichsupplemented oil output is directed by the governor to the pitch controlmechanism I4 for use thereby during feathering, unfeathering.,reversing'and unreversing operations of the propeller blades. I3.

Associated with the governor 2| cand adapted to aiect the oil supplyingvoperations 'thereof are a solenoid valve member 33 and a pressureswitch 34. The solenoid valve33 lis of 'a suitable constructionvadapting it to direct the Aow of high pressure auxiliary oil fromconduit 32 so that it, in a manner well known in the art, `supplementsthe pressure of the normal oil provided by the governor 2| on either theinboardor the outboard side of the piston I6 as-required to change theangle of the propeller blades` I3. The. pressure switch 34 is providedto stop the loperation of the pump 26 when the oil pressure in propellercylinder I-| builds up to a predetermined value.. '.The pressure switch34 lisoperatively connected to L actuation of the switch 38 thepropeller governor 2| so that the oil pressure diierential across thepropeller piston I6 is duplicated in the pressure switch 34, thus whenthe oil pressure in cylinder II builds up to the cut-out value of switch34 after the completion of either a propeller feathering or a propellerreversing operation the switch breaks the electrical circuit to themotor 2'| of pump 26, in a manner and through the use of variousmechanisms to be hereinafter described in detail, to close ci theauxiliary pressure being provided to the piston Iii and return the pitchchanging mechanism to the normal control of governor 2|.

A usual relay 35, 'electrically connected to the electric motor r2`|through a conductor 35, directly controls the now of current to themotor 2i for energization and deenergization thereof.

Carried by a propeller blade I3 is a slip ring 31 `oi usualconstruction, which slip ring is connected to an electricalinstrumentality or propeller reversing'control switch 33. The slip ring31 serves `to disrupt the current supply to the feather relay' todeenergize the feather pump motorV 2 to shut off the Aflow of auxiliaryoil from pump 26 when the propeller blades I3 have returned to positivepitch after an unreversing operation has occurred. This operation Ywillbe described in complete detail hereinafter.

A battery 4|, or any other primary current supply source, is provided tosupply the power for use in the operation of the control system 25.

The Vpropeller reversing control switch 33 constitutes the primarycontrol member in the control system 25 in that it controls the now ofcurrent from the battery M into the system. The solenoid valve 33,pressure switch 3A, relay slip ring 31 vand battery 5| are allelectrically connected to the propeller .reversing control switch terespectively through conductors 32, $3, ed, i5 and 46. The exactconstruction of switch 38 will be described in complete detail later.

In order to eiect reversing of propeller i i there 4must be an'actuation of the propeller reversing control switch 38, vand 'in thepresent invention, is accomplished through a suitable manually operatedthrottle control lever dl'which is provided with an arcuate cam surface63 adapted to engage with and oper'- ate the switch 38. The throttlelever di is Vutilized 'for operation of the switch 38 since it is acontrol member conveniently located for easy reach by the operator. Itis'to be understood that the particular construction of throttle controllever il forms lno 'part of this invention, as the inventioncontemplates the use of any usual engine throttle which can beassociated with the propeller reversing `control switch 38 in a mannerto permit the manual force applied to the throttle to be trans-- mittedto the .switch 38 to actuate the latter.

Referring now to Figures 1v to 4 inclusive, the construction of theelectrical instrumentality or propeller reversing control switch 38 istherein illustratedand as shown comprises a metallic cas ing or housing5I, formed with its ends and bottom open and having side walls 52 and 53and a top wall 54. To effect a closed structure the ends are closed bysuitable cover plates 55, only one of which is shown, and a base 56 ofmolded insulating material is tted across the bottom opening. Suitablestuds 51 threaded into the side walls 52 and 53 secure the cover plates55 and base 56 in place.v

Extending downwardly from the top wall 54 and inwardly, substantiallycentrally, from side wall 52 is a wall enlargement 58' having'v surfacesformed thereon against which generally L-shaped insulating members 6|can be disposed. Mounted `within housing 5|, one on each side of thewall projection 58, is a pair of similar unitary switch units 62 and 63.The switch units 62 and 63 are of` the snap-acting type and include apair of 'contacts 64 and 65 in spaced relationship and a movable contactmember 66 operable between these contacts but normally being biased intoen- .gagement with one of the contacts such as 64. The particularconstruction of the switch units is not a part of this invention. Forconvenience these switch units 62 and 63 may be of the type describedand claimed in Patent 2,237,705 to E. F. Kohl. For actuation in eachswitch unit of the snap-acting movable contact member 66 out ofengagement with contact 64 and into circuit making engagement withopposed Acontact 65 thereisl provided an outwardly biased operating pin61, which pin projects from the switch enclosing casingl and is 'adaptedto be depressed to provide the operating force for member 66.

`To individually actuate the operating pins 61 of the switch units 82and 63 there is located within the housing 5| and mounted between theunits 62 and 63 an actuator arrangement 68, the construction of which isbest shown in Figure 3. As there illustrated the actuator arrangement 68comprises a pair of pivotal lever means 1| and 12. Lever means 1icomprises a pair of generally L-shaped arms 13 and 14, which arms arepivotally mounted at their upper ends by a pin 15 upon a dependingportion or projection 16 provided by the top wall 54 of casing 5|. Attheir free ends the arms 13 and 14 rotatably support -a roller element11. Projecting from arm 14 and integral therewith is an extension 18which is bent to one side at substantially a right angle to arm 14. Itis this projection 18 which is adapted to engage and depress pin 61 ofswitch unit 63 upon pivotal movement, in a clockwise direction, of levermeans 1|.

Lever means 12 also comprises a pair of generally L-shaped arms 8| and82 which are mounted at one end for pivotal movement on wall portion 16by the pin 15 and are disposed so that arm 8| lies outside of arm 13 andarm 82 lies outside of arm 14 of the lever means 1|. The free ends ofthe'arms 8| and 82 also rotatably support a roller element 83. Formed onarm 8| is a projection 84 which is bent over to extend to the outside ofarm 8|. Projection 84 is adapted to contact and move pin 61 of switchunit 62 for operation of this switch unit.

Disposed within housing 5| opposite from switch units 62 and 63 andadjacent side wall 53 is an electromagnet 85 comprising a core 86 withan energizing coil 81 disposed thereabout. A stud 88 passed through topwall 54 is adapted to be threaded into core 86 to secure theelectromagnet 35 against the interior surface of top wall 54. A lockwasher and nut assembly 9| carried onstud 88 positions and maintains thestud in a ldesired positionas will be discussed in further detailhereinafter.

Associated with electromagnet 85 is a movable contact carriage assembly92 having an armature `member 83 extending beneath the electromagnet 85for cooperation therewith. Movable contact carriage assembly 92comprises a bracket member 94 having a plate-like portion 95 to theupper surface of which the armature 93 is secured by studs, or in anyother well known manner. The bracket member 94 includes a pair ofupstand- Zing arms `96"and '91' through whichthebracket member 94 ispivotally mounted by a pivot pin 98 upon a wall portion |0| dependingfrom the top wall 54. Upwardly bent from the portion 25 are a pair oflugs or ears |02 which are provided to support rotatably a rollerelement |03. To the under face of bracket member 94 is suitably fasteneda pair of rectangular insulating blocks |04 and |05, with insulatingblock |04 disposed intermediate bracket 94 and block |05. Supported inhorizontal alignment by the insulating blocks |04 and |05 are aplurality of generally L-shaped conducting pieces |06, |01 and |08, eachhaving one leg |09 disposed and tightly pressed between the insulatingblocks |04 and 05, and having a free leg extending downwardly from thesupport aiorded by the blocks |04 and |05, with appropriate contact.faces ||2 being carried by these free legs As shown in the drawings theends of legs |09of conducting pieces |06, |01 and |08 extend beyondtheir engagement by blocks |04 and |05 to provide attachment points forelectrical leads. The depending legs of the conducting pieces |06, |01and |08 are adapted to engage and disengage a plurality of contactmembers mounted on and extending from insulating base 56 for making andbreaking electric circuits therethrough. As indicated on the Wiringdiagram of Figure 10 conducting piece |06 cooperates with a stationarycontact member 3, central conducting piece |01 is engageable with a pairof stationary contacts ||4 and ||5. and conducting piece |08 makes andbreaks a circuit through stationary contact member 6. The variousstationary contacts ||3, I4. 5, and ||6 comprise flexible upstandingportions ||1 to perm-ita slight sliding engagement with contact faces||2 for the purpose, as is well known in the art, of lessening anytendency to burn or pit of the contacts.

A resistor member ||8 is mounted through a bracket |2| on side wall 53of housing 5| and lserves to limit the amount of current passed to theenergizing coil 81 of the electromagnet 85.

Located adjacent and above resistork ||8 is a stop member |22 formed byan integral portion bent outwardly from bracket |2|. Stop member |22A isadapted to be engaged by the armature member 82 to determine the extentof movement of this member away from the eleotromagnet 85. A usual wirespring means |23 having a portion thereof wound around pivot pin 98 andwith one end bearing upon bracket member 94 and the other end positionedagainst the inner surface of top wall 54 biases the contact carriageassembly 92 for movement in a clock-wise direction, as viewed in Figures1 and 2, to move the armature member 93 against stop |2| and normally tomaintain the depending legs of pieces |06, |01 and |08 disengaged fromtheir respective cooperating stationary contacts.

, There isincluded in control switch 38 a mechanism for moving pivotallythe contact carriage assembly 93 and the two lever means 1| and 12 ofactuator arrangement 68. This mechanism includes a reciprocal elongatedplunger |24 extending through the top wall 54 of housing 5| and into thehousing 5| to lie disposed between .the actuator arrangement 68 and thecontact 'aflixed a generally cup-shaped washer member .|26.4 Aspring|21encircling theoutwardly disposed portion of plunger |24 and having oneend .seated against washer |26 and the other against Vthe housing '5|exerts its bias-to urge the plunger |24 outwardly from casing 5|.

The portion of plunger |24 disposed within casing and extendingV belowthe lower end of bushing member |25 is provided with a generallyV-shaped circumferential camming ridge |28. va large diameter portion|3| which is connected through a slope to a small diameter portion |32,

which latter portion in turn is connected by a sloping portion to aprojecting portion |33, extending directly downwardly .from smalldiameter portion |32. Camming ridge |28 being of larger diameter thantheiower end of bushing |25 prevents the removal of the plunger |24through the top wall 54.

For reciprocal operation of the plunger |24 an actuating arm |34 isprovided which is pivotally mounted at one end |35 to a generallyU-shaped mounting bracket member |35 suitably secured as by stud. means|31 tothe top wall 54. The free end |38 of arm |34 carries a generallyU-shaped bracket |4| which rotatably supports a rollerv |42. Rollei' |42isvadapted to be engaged bycam surface 430i throttle control lever 41 toellect pivotal movement, in a counter-clockwise direction, of the arm|34 toward the housing 5|. To the undersurface of arm |34 is secured oneend of. a leaf .spring .element |43. The iree end of spring element |43bears against a projection '|45 provided at the outer end of plunger|24. Spring element |43 functions as an over-travel device 'in thetransmittal of motion from arm |34 to plunger |24. .To adjust theposition of the free end of arm |34 use is made of the stud 88 Ywhich.mounts the electromagnet 85 within casing .5 yStud 85 is adapted toproject through a keyhole slot |45 inarm |34 so that its head |46 mayengage the upper surface arm |34 and apply a holding force .thereagainstStud 88 will permit the roller ,|42 .to .be adjusted to the bestposition for cooperation with cam. surface 48 onthrottle control lever41.'V

, Reference will now had rto the wiring diagramof Figure 10. `Thisiigure illustrates the .incorporation of tlie reversing control system25 with-the feathering control system for. the propeller li. Combiningthe two systems permits the utilizationby both control systems cicertainof the sameY devices, such as the solenoid valve 33, pressure switch 34,relay 35, the electric motor driven pump 25, and the propeller bladeslip ring 31.

. Further provided to complete-the feathering control system are apush-pull electric switch |46 .contact |52 in either direction from itsnormallycontacts disengaged position into circuit-making engagement withthe 4various contact sets of switch |46. The hold-in coil |54 functionsto maintain actuator |53 `in its depressed or in position. Hold-in` coilv|54 is electrically connectedat one end to contact |5611l and isV con-.n'ectedv at .its other end byV electrical lead |55 to groundthroughimessureswitch 34.

The double-pole relay |41 embodies a pair of switch arms |56 and |51 andan energizing coil |58 operatively connected to the switch arms |56 and|51 for movement thereof from their nornially open positions intocircuit making positions. The double pole relay |41 and the pushpullswitch are electrically interconnected with switch arm being connectedthrough leads |53 to contacts |49a and |491), switch arm l|51 beingconnected by lead |6| to contact |56a, and coil |58 being connected atone end to contact |5|a through lead |52. The other end of coil |58 isjoined by lead |63 to blade brush |64. Blade brush |64 is adapted tocooperate with contact segments |55 and |55 when propeller blade i3rotates to complete a circuit to ground for purposes to be described.

Switch arm |55 on energization of coil |58 engages contact |61 of relay|41 which is connected by appropriate electrical leads |68 to pump relay35. It is noted that one of these leads |53 extends between contact |5|bof `pushpull switch |45 and pump relay 35, connecting to energizing coil|53 of the relay.

Switch arm |51 on energization of coil |56 moves into engagement withstationary contact |1| which. connects through lead |12 to solenoidvalve 33.

Direct current power to the push-pull switch V|45 is provided throughlead |13 which connects to both contacts Idea and |481). This power maybe taken from any primary current supply source, and, conveniently couldbe led from battery 4|.

The electric connections from propeller reversing control switch 38 tothe various devices re.- quired to effect reversing of the propellerwill nowy be discussed.

Lead 42 interconnects the solenoid valve 33 with movable contact arm 65of switch unit 53. Contact 55 of switch unit 53 is connected byconductor |14 to contact Yiwhich cooperates with conducting piece $68 ofVmovable contact carriage 92. Stationary Contact 55 of `switchunit 53 isconnected by lead 45 to battery 4| which in turn is connected through anappropriate lead |15 to contact |15 of relay 35. Contact |16 is adaptedto be engaged by movable contact |11 on energization of coil |53y tocomplete a circuit through lead 35 to pump motor 21. Stationary contact55 or switch 63 is adapted to be connected also to normally engagedstationary contact 54 of switch unit 62 by a lead |18. Oppositelydisposed contact 55 connects through .lead |81 to switch unit 53 andthence through lead 42 to solenoid valve 33.

Pressure switch 34 is connected to one. end of energizing coil 31 ofelectromagnet 85 by lead 43. This same end of coil 81 is then connectedby flexible lead |82 to conducting piece' Hi8.V The opposite end of coil81 is connected by flexible lead |83 to conducting piece |01. A nexiblelead `|54 connects conducting piece |56 to switch unit 62. Stationarycontact ||3 which is engageable by movable conducting piece |65 isconnected by lead .44 to energizing coil |69 of4 relay 35. Stationarycontact i4 engageable by lconducting piece |61 connects through lead |66to resistor IIB which latter is connected to power supply lead 45 by alead |35. Stationary contact ||5 is also engageable by conducting piece|61 to complete a circuit through appropriate leads |63 and |85 to blade`brush |64 of the slip ring. as-

sembly 31. It is' understood that push-pull switch |46 and double-polerelay |41 do not enter into the control of the reversing and unreversingmovements of the propeller l They are included merely to complete thefeathering control system to illustrate that feathering control ofpropeller I and reversing control of propeller I involves common use ofa substantial number of control elements to avoid duplication of parts.

Since the feathering of propeller is incidental to the present inventionthis operation will be described only briefly. To effect feathering ofpropeller the actuator button|53 is depressed. This will energize coil|59 of relay 35 to close the circuit to motor 21 to start operation ofpump 26. Hold in coil |54 is also energized by current iiowingtherethrough to ground through pressure switch 34. Pump 26 continues tosupply iiuid to governor 2| to cause it to provide preslsure to theoutboard side of piston I6 to rotate propellerblade segments 3 towardhigh pitch and feather position. As soon as the position is reachedmechanical stops, not shown, in well known manner halt the blades andcause the pressure in the governor to build up to a predetermined value,at which the pressure switch 34 is adapted to cut out and break thecircuit therethrough. This results in de-energization of holdin coil |54and actuator |53 returns to its neutral position whereby the pump 26stops and the feathering operation is completed.

To unfeather propeller the actuator |53 is manually moved in the reversedirection to cause movable contact I52 to bridge contacts |48a, |49a,l|5|la and |5|a. With the bridging of these contacts coil |58 of relay|41 is energized by completion of a ground through brush |64 resting oncontact segment |66. Arms |56 and |51 move to circuit making position toenergize solenoid valve 33 and relay 35. Fluid will then iiow from pump'26 through governor 2| to the inboard side of piston I6 to rotatepropeller blade segments |3 to assume a low pitch angle. When apredetermined blade angle is attained an insulated portion on slip ring31 is presented to brush |64 to break the circuit to relay |41,deenergizing it and inactivating pump 26.

Propeller reversing and unreversing-operations will now be described.Assuming the propeller I I to be functioning in normal, or low pitch,condition the propeller reversing control switch 38 will have itsoperating parts disposed in the positions illustrated in Figures 1, 2and 9. As seen pivoted arm I 34 will be in its upper position, as willplunger |24. Roller |03 carried by contact carriage assembly 92 will lieadjacent large diameter portion |3| of plunger |24 and beneath cam.-ming ridge |28. Roller 11 of lever 1| will be disposed contiguous smalldiameter plunger portion |32, while roller 83 of associated lever 12abuts plunger projection |33.

When it is desired to reverse propeller the throttle control lever 41 isoperated to move cam surface 48 upon roller |42 carried by pivoted arm|34 to rotate arm |34 toward the top of casing 5| of reversing controlswitch 38. This movement of arm |34 applies a force to the upper end ofplunger |24 to move it longitudinally, against the bias of spring |21,into casing 5|. As plunger |24 moves rectilinearly toward base 56 thelowermost roller 83 will ride from projection |33 onto small diameterportion |32 to actuate switch unit 62, camming ridge I 28 will engageuppermost roller |03 to position armature 93 adjacent coil 81 andintermediate roller l11 will ride upon large diameter portion |3| 10before camming ridge |28 passes beneath upper roller |03.

Reference should now be had to Figure 10 to describe the results of theactuation of plunger |24. Riding up of lowermost roller 83 onto smalldiameter plunger portion |32 will pivot lever 12 to cause projection 84thereon to depress actuating pin 61 of switch unit 62. This will causemovable contact 66 to move from contact 64 into engagement with opposedstationary contact 65. Engagement of uppermost roller |03 by plungercamming ridge |28 rotates contact carriage assembly 92 to position, asstated, armature 93 adjacent coil 81 and, further, to bring conductingpiece |06 into engagement with stationary contact ||3, conducting piece|61 into engagement with stationary contacts and ||5 and conductingpiece |08 into engagement with stationary contact ||6. With contact ||4engaged by conducting piece |01 current can be supplied through resistor||8to energize coil 81 of electromagnet 85 to hold armature 93 in closedposition and thereby maintain contact carriage assembly 92 in actuatedposition. Intermediate roller 11 riding onto large diameter plungerportion 3| pivots lever 1| to cause projection 18 thereof to depressactuating pin 61 of switch unit 63. This causes movable contact arm 66to engage stationary contact 65 of switch unit 63 to complete thecircuit to solenoid valve 33. Furthermore current can now flow frommovable contact arm 66 of switch 4unit 63 through lead |6| to movablecontact arm 66 of switch unit 62, from which it passes by way of lead|84 through engaged contacts |66-||3 to lead 44 and then to coil |69 ofrelay 35. Relay 35 now functions to energize motor 21 to run pump 26 tobegin the operation of reversing propeller At this point the relativepositions of the elements of reversing control switch 38 are asillustrated in Figure 6. Pump 26 directs a ow of oil through thegovernor 2|,and through line 22 to the cylinder I1 at the rear of pistonI6 to effect rotation of the propeller blade segments |3 into reverseangle position. At the end of the reversing operation pressure builds upto a predetermined value to actuate pressure switch 34 to break thecircuit through electromagnet coil 61 to release armature 93 therebypermitting contact carriage'assembly 92 to rotate under the bias ofspring |23 into its neutral position. This causes conducting piece |06`to separate from stationary Contact 3 to break the circuit to relay 35to inactivate pump 26, Solenoid valve 33 remains energized Vthroughswitch 63 and serves to hold the propeller in its reversed position.Figure 7 is illustrative of the relative positions of the elements ofreversing control switch 38 when propeller is reversed.

To unrev'erse propeller `and return it to normal-position the throttlecontrol lever is operated to disengage camming surface 48 from roller 48on arm |34. This permits plunger 24 to move upwardly under the bias ofits spring |21. In this movement ofplunger |24 intermediate roller 11will ride off of large diameter plunger portion 3| permitting lever 1|to be rotated away from switch unit 63 under pressure of the outwardlybiased pin 61 of switch unit 63. Contact arm 66 thereupon disengagescontact 65 and returns 4to its 'normally engaged position on stationarycontact 64. This results in the breaking of the circuit to solenoidvalve 33. Cam |28 engages uppermost roller |03 to Il rotate contactcarriage assembly 62 to effect engagement betweenv theconductinglpieces" |06, |01 and |08 and their cooperating contacts H3,||4, I5 and I I6. Power will'then be supplied to energizingelectromagnetic coil 81 through resistor ||8 and contacts ||4 and |01 tocause coil 81 to hold armature 93 adjacent thereto and thereby maintaincontact carriage assembly 92 in rotated position. Normally ground forthe coil 81 is provided through lead 44 and pressure switch 34. Howeverin the event that pressure switch 34 fails to .bev in closed positioneither because of a pressure surge in the flow lines or because thethrottle was moved so fast that it did not have suicient time to close asecondary groundis provided.v This secondary ground is had through lead|02, engaged contact elements |06 and ||6, lead |14, movable contact arm66 of switch unit 63p lead 4,2 and then through solenoid valve 33. Thisinsures that acircuit is provided for the coil 81 for maintaining thecontact carriage assembly in operated position.v

Further upward movement of plunger |24 now permits lowermost roller 83to travel from small diameter plunger portion |32. This relieves thepressure on pin 81 of switch unit 62 permitting the pin 61 to moveoutwardly and rotate lever 12. Movable contact arm 66` now disengagescontact 55 and re-engages stationary contact 64 to complete a'circuitfrom battery 4| through engaged conducting piece |06 and contact ||3 tolead 44 and to coil |69 of relay 35. Relay 35 now energizes motor 21 andstarts pump 25. This stage the positions of the elements oi reversingswitch 38 are as illustrated in Figure 8. Oil pressure will now berouted by the governor 2| through line 23 to cylinder |1 to the outboardside of piston I6, Piston |6 moves to rotate propeller blade segments |3into positive normal thrust angle. When the propeller segments I3 reachpositive pitch contact |65 of the slip ring assembly 31r engages brush|64. This results in shorting out of electromagnetic coil 81 throughcontact ||5, conducting piece |01, lead |86 and lead |63. armature 9,3and permits contact carriage 92 to return under spring biasA to itsnormal position. as shown in Figure 9, to` disengage conducting piece|06 and contact I3 to interrupt the circuit to relay 35 and stop pump 26and thus return the system to its normal condition.

While certain preferred embodiments of; the invention have beenspecifically disclosed, itis understood that the invention is notlimitedthereto as many variations will be` readily apparent to those skilledyin the art. and the invention is to be given its broadest possibleinterpretation within the terms oi'v the following claims:

I claim:

. 1. An electricV circuit controllinginstrumentality comprising a pairof` electric switches, a nrst movable means for operating one of saidelectric switches,y a second movablemeans for operating De-energizationof coil B1 releases the other of said electric switches, anelectromagnet, an armature normally spaced from said electro-magnet andmovable toward and away from said electro-magnet, a movable contact, astationary contact, a switching member mounting said movable contactnormally spaced from said stationary contact, said switching memberbeing operatively connected to, said armature. and movable therewith`to, perform aswitching operation, and actuatingmeans movable to actuatesaid iirst and second movable means t9 operate said pair of emetrieswitches, said actuating means, in the same movement,v moving-saidswitching member to engage said movable coritact with saidstationarycontact, and moving said amature into position to beheldmagnetically by the electro-magnet.

2. In an electric circuit controlling instrumentality comprising ahousing, a pair of electric switch means supported in said housing, afirst pivoted lever means for operating one of said electric switchmeans, a second pivoted lever means for `operating the other of saidelectric switch means, an electro-magnet mounted in said housing, amovable armature normally spaced from said electro-magnet, a movablecontact, a stationary contact, a switching member mounting said movablecontact normally spaced from said stationary contact, a movablesupporting member mounting said armature and said switching member forcommon movement, and a Vreciprocable actuating plunger `movable. toactuate said first and'second lever means to operate said pair ofelectric switches, said plunger, in this same movement, actuating saidsupporting member to move said switching member to engage said movablecontact with said stationary contact and simultaneously move saidarmature into position to be held magnetically by the electro-magnet.

3. In an electric circuit controlling instrumentality comprising ahousing, a pair of electric switch means supported in said housing, afirst pivotally `mounted lever meansV for operating one of said electricswitch means, a second pivotally mounted lever means for operating theother of said electric switch means, an electro-magnet mounted in saidhousing spaced from said pair of electric switch means, a movablearmature normally spaced from saidl electro-magnet, a movable contact, astationary contact, a switching member mounting said movable contactspaced `from said stationary contact, a pivoted supporting membermounting said armature and said switching member for common movement,and an axially movable actuating plunger, slidably supported by saidhousing, movable to actuate said iirst and second pivotally mountedlever means to operate said pair of electric switches, said actuatingmeans, in this same movement, actuating said pivoted member to move saidswitching member to engage said movable contact with said stationarycontact 'and at the same time to move said armature into position to beheld magnetically bythe electro-magnet.

4. In an electric circuit controlling instrumentality comprising ahousing, an actuating plunger slidably supported by said housing forendwise movement, a pair of electric switch means supported in saidhousing, pivotally mounted means for operating said pair of electricswitch means, with the pivot axis of said means being disposed at oneside of the plunger, anA electro-magnet mounted in, said housing spacedfrom said pair of electric switch means, a movable armature normallyspaced from said electro-magnet, a switching member, a pivotedsupporting means mounting said armature and said switching member forcommon movement, with the pivot axis of said pivoted supporting meansbeing disposed on the opposite side of saidy plunger from said firstmentioned pivot axis, means for moving said actuator plunger to actuatesaid first and second pivotally mounted lever means to operate said pairof electric switches, said actuating plunger, in vthis same movement,actuating said pivoted supporting means to move said switching mem- 13ber to perform a switching operation and at the same time to move saidarmature into position to be held magnetically by the electro-magnet.

5. In an electric circuit controlling instrumentality comprising ahousing, a pair of electric switch means supported in said housing, arst pivotally mounted lever means for operating one of said electricswitch means, a second pivotally mounted lever means for operating theother of said electric switch means, an electro-magnet mounted in saidhousing spaced from said pair of electric switch means, a pivotallymounted armature normally spaced from said electromagnet, a switchingmember operatively connected to said armature for movement therewithbetween circuit-making and circuit-breaking positions, an actuatingplunger movably supported on said housing for endwise movement, a rstportion on said actuating plunger for engaging said pivotally mountedarmature, on movement of said plunger, to move said armature into,position closely adjacent said electro-magnet to be held magneticallythereby on energization of the electro-magnet, a second portion on saidactuating plunger for engaging the rst pivotally mounted lever formovement thereof to operate its associated electric switch, and a thirdportion on said actuating plunger for engaging the second pivotallymounted lever means for moving it to operate its associated electricswitch, said switching member moving, on movement of said armature, intocircuit-making position. i

6. In an electric Acircuit controlling instrumentality comprising ahousing, a reciprocable actuating plunger, a pair of electric switchmeans supported in said housing, a rst pivotally mounted lever means foroperatingone of said electric switch means, with the pivot axis of saidlever means disposed on one side of said plunger, a second pivotallymounted lever means for operating the other of said electric switchmeans, with the pivot axis of this latter lever means mounted on thesame side of said plunger as is the pivot axis of the first lever means,an electromagnet mounted in said housing spaced from said pair ofelectric switch means, a movable armature normally spaced from saidelectromagnet, pivoted supporting means carrying said armature, thepivot axis of said supporting means being disposed on the opposite sideof said plunger from said rst mentioned pivot axis, a switching memberoperatively connected to said armature for common movement therewithbetween circuit-making and circuit-breaking positions, a camming portionon said actuating plunger for engaging said pivoted armature supportingmeans, on movement of said plunger, to move said armature into positionadjacent said electro-magnet to be held magnetically thereby onenergization of the electro-magnet, a large diameter'portion on saidactuating plunger for engaging the rst pivotally mounted lever means formovement thereof to operate its associated electric switch, and a smalldiameter portion on said actuating plunger for engaging said secondpivotally mounted lever means for moving it to operate its associatedelectric switch, said switching member moving, on movement of saidarmature, into circuit-making position.

7. In an electric circuit controlling instrumentality comprising ahousing, a longitudinally movable actuating plunger slidably mounted onsaid housing having an end movable within the interior of said housing,a pair of electric switch means supported in said housing, a firstpivotally mounted lever means for operatingoneofsaid electric switchmeans, a roller rotatably supported by said lever means, a secondpivotally mounted lever means for operating the other of said electricswitch means, a roller rotatably supported by this second lever-means,an electromagnet mounted in said housing spaced from said pair ofelectric switch means, a movable armature normally spaced from saidelectromagnet, a switching member, a pivoted supporting means mountingsaidV armature and said switching member for common movement, a rollermounted for rotation on said pivoted supporting means, a camming portionon said actuating plunger coacting with the roller on said pivotedarmature supporting means to move said switching member intocircuit-making position and to move said armature into positionimmediately adjacent said electro-magnet to be held magnetically therebyon energization of the electro-magnet, a large diameter portion coactingwith the roller on the rst pivotally mounted lever means for movementthereof to operate its associated electric switch, and a small diameterportion on said actuating plunger for engaging said second pivotallymounted lever means for moving it to operate its associated electricswitch.

8. In an electric circuit controlling instrumentality comprising ahousing, an actuating plunger slidably supported by said housing forendwise movement therein and comprising a cam portion. a large diameterportion, a small diameter portion and a projecting portion extendingfrom theend of the small diameter portion, a pair of electric switch-means supported in said housing, a rst pivotally mounted lever meansfor operating one of said electric switch means, with the pivot axis ofsaid lever means disposed on one side of said plunger, a rollerrotatably supported by said lever means and abutting said small diameterportion, a second pivotally mounted lever means for operating the otherof said electric switch means, with the pivot axis of said second levermeans mounted on the same side of said plunger as is the pivot axis ofthe rst lever means, a roller rotatably supported by said second levermeans contiguous to said projecting portion on said plunger, anelectromagnet mounted in said housing spaced from said pair of electricswitch means, a movable armature normally spaced from saidelectromagnet, a switching member, a pivoted supporting member mountingsaid armature and said switching member for common movement, the pivotaxis of said supporting means being disposed on the opposite side ofsaid plunger from said rst mentioned pivot axes, a roller mounted forrotation on said pivoted supporting member and abutting said largediameter portion, and means for moving said actuating plunger in a rstdirection to move said roller carried by said second lever means, intoengagement with said small diameter portion thereby to move said secondlever means to operate its associated electric switch, said movement ofsaid actuating plunger causing said camming portion to coact with theroller on the pivoted armature supporting member to move the switchingmeans to perform a switching operation and to move the armature intoposition immediately adjacent said electro-magnet to be heldmagnetically thereby on energization of the electro-magnet, thismovement of actuating plunger in a rst direction also causing the largediameter portion of the plunger to coact with the roller on the rstpivotally mounted lever. means izomove -saidiirst lever means to operateits associated electric switch.

9; In an electric circuit controlling instrumentality comprising ahousing, a longitudinally movable actuating plunger slidably mounted onSaid housing having an end movable within the interior of said hcusing,apair of electric switch means supported in said housing, a rst pivotallymounted lever means mounted adjacent said plunger, for operating one ofsaid electric switch means, a roller rotatably supported by said levermeans to be positioned abutting said plunger spaced from the interiorend thereof, a second pivotally mounted lever means mounted adjacentsaid plunger and on the vsame side thereof as the rst lever means foroperating the other of said electric switch means, a roller rotatablysupported by this second lever means and abutting on said plunger closerto the end thereof than said roller on said first lever means, anelectromagnet mounted in said housing spaced from said pair of electricswitch means, a movable armature normally f spaced from saidelectromagnet, a switching member, a pivoted supporting means,positioned adjacent said plunger on the opposite side thereof than. saidrst and second lever means, mounting said armature and said switchingmember for common movement, a roller mounted Vfor rotation on saidpivoted supporting means and in abutment on said plunger farther fromthe end thereof than the other two rollers, a camu-ring portion on saidactuating plunger coacting with the roller on said pivoted armaturesupporting means to move said switch-v ing member into circuit-makingposition and to move said armature into position immediately adjacentsaid electro-magnet to. be held magnetically thereby on energizatgion ofthe. electromagnet, alarge diameter portion coacting with the roller onthe first pivotally mounted lever means for movement thereof to operateits associated electric switch, and a small diameter portion on saidactuating plungerl for engaging said second pivotally mounted levermeans for moving it to operate its associated electric switch.

l0. In an electricr circuit controlling instrumentality comprising a:housing, a pair of electric switch means supported in said housing, afirst pivotally mounted lever means for operating one ating plunger forurging said plunger in a rst direction,` and movable means mounted uponthe exterior of said housing for engagingand moving said actuatingplunger in the opposite, direction and against the action of saidspringmeans to actuate said rst and second pivotally, mounted lever means tooperate said pair of electric switches, said actuating plunger in thissame movement, actuating said pivoted supporting member to move saidswitching member to perform a switching operation and simultaneouslymoving said armature closely7 adjacent said electro-.magnet in positionto be held magnetically by the electro-magnet.

11.111 an electric circuit controlling instrumentality comprising ahousing, a pair of electric switch means supported in saidl housing, afirst lever means for operating one of said electric switch means, asecond lever means for operating the other of said electric switchmeans, anelectro-magnet mounted in said housing, a movable armaturenormally spaced from said electromagnet, a switching member, a movablesupporting member mounting said armature and said switching member forcommon movement, and a reciprocable elongated actuating plungerslidablysupported by said housing and extending from the exterior thereof intooperative position within said housing, spring means operativelyconnected to said plunger for urging it for movement outwardly of saidhousing, and a pivotal member mounted upon the exterior of said housingfor engaging the exteriorly disposed end of the plunger to move saidplunger inwardly and against the action of said spring means to actuatesaid first and second lever means to operate said pair 0fy electricswitches, said plunger in this same movement, actuating said supportingmember to move said switching member to perform a switching operationand simultaneously move said armature closely adjacent said electroofsaid electric switch means, `a second pivotally magnet inV position tobe. held magnetically by the electro-magnet.

LAWRENCE J. BORDELON.

REFERENCES CITED The following references are of record in the iile ofthis patent:

lUNITED STATES PATENTS Number Name Date 800,098 McCarty June 10, 18841,731,39l Mottlau Oct. 15,1929 2,155,586. Ebert o Apr. 25, 19392,181,829 Jeffrey Nov. 28, 1939 2,266,784 Matteucci p Dec. 23, 19412,298,068 Pierce v Oct. 6, 1942 2,306,355 Gensburg g Dec. 22, 19422,372,102 Mahnke Mar. 20, 1945 2,468,974 Hammer May 3, 1949 2,503,632Prather -i Apr,' 1,1, 1950

